Update feature flag for HTML5 media recorder
Update feature flag for HTML5 media recorder

This commit renames the feature flag to HTML5 Media Recorder in
RCE; it previously included Arc because it was built by the Arc
team but does not directly relate to the Arc product. Also
updated the flag to allow visibility in beta.

REFS: COMMS-1486

Test plan:
- Log in to Canvas as an admin
- Open Account Settings
- In Account feature options, make sure you can view the
HTML5 Media Recorder in RCE feature option with the
development label and that the feature can be toggled on

Change-Id: I47d40263ba3dd91ad0bcca9b14ca7ba83409e323
Reviewed-on: https://gerrit.instructure.com/167716
Tested-by: Jenkins
Reviewed-by: Landon Gilbert-Bland <60d9ff23682c863d36b48b4c32c5ce5f434d29c0@instructure.com>
QA-Review: KC Naegle <9fbecd016338f9910821a8a5d5d0ae4fc9abfaa5@instructure.com>
Product-Review: KC Naegle <9fbecd016338f9910821a8a5d5d0ae4fc9abfaa5@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms